Greenmask

Greenmask is a free, open-source utility for PostgreSQL logical backups, data transformation, anonymization, and restoration. It is best suited to teams building repeatable database workflows for development, testing, or other data use. Its combination of configurable masking, validation, and familiar PostgreSQL restore compatibility is compelling, provided PostgreSQL is the only engine you need.

Overview

Greenmask handles data through logical dumps and does not require changes to the existing database schema. Its dumps can be restored with pg_restore, which makes it a practical fit for teams already using PostgreSQL utilities. Alongside backups and restoration, it supports anonymization and synthetic data generation.

This is a focused database utility, not a broader security monitoring suite. It supports data masking, but does not provide activity monitoring, access governance, audit reporting, or threat detection. Teams that need those controls should consider a broader security product.

Key features

Transformations can be deterministic or random, use dynamic parameters, and apply custom domain-based rules. Configuration validation can surface warnings, transformation diffs, and schema diffs, helping teams review the effects of transformations and changes to schemas. Configurations can also be inherited across partitions, reducing repeated setup for partitioned tables.

Parallel dumping and restoration, together with parallel compression using pgzip, can help speed up data workflows. Greenmask stores dumps in local directories or S3-like remote storage, and can integrate with CI/CD systems to automate anonymization and restoration. That combination suits teams that want repeatable data preparation within existing delivery processes.

The maker provides a Docker playground with sample databases for trying the utility. Installation options include an install script, Docker, Homebrew, or building from source. The install script supports Linux and macOS; Windows is not supported yet.

Pricing

There is no paid subscription plan or free trial. The utility is deployed on premises. For urgent or enterprise-specific feature requests, the maker offers paid custom development, so organizations needing tailored work should account for a separate cost.

Platforms

Greenmask supports Linux and macOS, as well as self-hosted deployment. It is not yet supported on Windows. Database coverage is currently limited to PostgreSQL; support for MySQL, MongoDB, and other engines is in development. That makes it a poor fit for teams that need one tool for a mixed-database estate today.

Who it's for

Data engineers, DevOps teams, software developers, and machine learning teams can use Greenmask to build repeatable workflows for backing up, transforming, and restoring PostgreSQL data. Healthcare and finance organizations are also among its intended users. Its masking and validation features suit teams preparing data for other uses, while its PostgreSQL-only scope and lack of monitoring or governance features limit its role in broader security programs.

Pros and cons

Pros

• Useful transformation controls: Deterministic and random methods, dynamic parameters, and custom domain-based rules support configurable data anonymization.
• Review before relying on transformed data: Validation warnings and transformation and schema diffs help teams inspect likely changes.
• Fits PostgreSQL workflows: Dumps work with pg_restore, and logical dumping avoids changes to the source schema.
• Automation and storage options: CI/CD integration and local or S3-like storage support repeatable workflows.
• No software charge: The open-source plan costs nothing.

Cons

• PostgreSQL only today: Teams using MySQL, MongoDB, or other database engines cannot yet use Greenmask across those systems.
• No Windows support: Windows users need another environment or another utility.
• Not a complete database security platform: It lacks activity monitoring, access governance, audit reporting, and threat detection.

Alternatives

MySQL is worth considering when you need a free plan and broad platform support, including Windows; its free trial and freemium pricing model may also suit readers exploring a different database option.

DataVeil may suit teams seeking database masking with a free license that never expires. Its Community License covers databases up to 10GB and includes free dataset and user SQL masks, with premium masks limited to 200,000 values per the plan description.

Oracle Cloud Infrastructure Secret Management is an alternative for readers looking for a free secrets management service with API and web platforms.

DSGuard may be a fit for teams seeking a self-hosted, no-cost database security option with unlimited datasources and users, and no stated time or capacity limit.

Trellix Data Loss Prevention is aimed at organizations seeking enterprise data loss prevention across endpoints, email, web, networks, and data storage, with on-premises or SaaS management.

Lopam.AI Database Activity Monitoring is the more relevant option when database activity monitoring or custom database integrations are the priority; its pricing is custom.

Satori Data Security Platform and AI Tech Secure Database Security are paid alternatives for readers comparing other database security products.

Browse Database Security Software for more options.

Verdict

Greenmask is a strong choice for teams that need a free, self-hosted way to anonymize, transform, back up, and restore PostgreSQL data. Its validation tools, automation support, and compatibility with pg_restore make it especially useful in repeatable data workflows. Look elsewhere if Windows support, additional database engines, or broader security monitoring and governance are requirements.